The present invention relates to a data storage apparatus. More particularly, the invention relates to methods of forming servo tracks on storage apparatus media, and a data storage apparatus having servo tracks formed using said method.
A hard disk drive (HDD) is an apparatus for writing data to or reading data from a rotating, disk-type magnetic recording medium using a read/write head located above the recording medium. In order to manufacture a HDD with a high recording density, the dense formation of the servo tracks on the recording medium is essential. Conventional servo writing technology was limited for some time to the formation of servo tracks on a HDD having a density of about 300 kTPI.
More recently, a method of forming servo tracks on a HDD using magnetic printing techniques has been introduced. Magnetic printing is a method of applying a magnetic material to the surface of a magnetic disk including servo tracks. The constituent data storage apparatus is thus enabled to store data according to a defined magnetization direction. While magnetic printing has allowed improved servo track densities, it nonetheless suffers from certain noise issues. For example, noise may occur in a non-signal field portion (e.g., a buffer field) of a servo track. This type of noise may lead to the generation of a direct current (DC) offset in a reproduced data signal. Undesired DC offsets deteriorate the quality of the reproduced data signal and may in certain circumstances cause malfunction of the data storage apparatus.